Improvement in converting motion



T. A. MAGAULAY;

CONVERTING MOTION.

No. 41,780. Patented Mar. 1, 1864.

UNITED STATES PATENT OFFICE.

r. A. MAOAULAY, or NEW YORK, N. Y.

IMPROVEMENT IN CONVERTING MOTION.

Specification forming part of Letters Patent No. 41, 7 80, dated March 1, 1864.

To all whom it may concern.-

Be it known that'I, T. A. MACAUL'AY, of the city, county, and State of New York, have invented a new and Improved Device for Oonvertin g Rotary into Irregular Reciprocat- .in g Motion; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Fignrel is a front view, showing the application of my device to the needlebar of a sewing-machine. Figs. 2and 3 are views of the device at right angles to-Fig. 1, showing it in different positions. Fig. 4 is a diagram llustrating the movement of the crank-wrist.

Similar letters of reference indicate corresponding parts in the several figures.

This invention may be characterized as avariable'crank. Its novelty consists in a pcculiar mode of connecting the wrist with the wrist-plate or body of the crank, whereby as it revolves it is at the same time caused to move toward and from the axis of the shaft and produce an irregular reciprocating motion of any body with which it is connected. The invention is applicable to the needlemotion of sewing-machines and to other purposes.

To enable others skilled in the art .tiiginake and use my invention, I will proceed to describe its construction and operation;

A, Fig. 1, represents a portion of the frame of a sewing-machine.

B is the ncedlebar, arranged in guides in the usual manner.

0, Figs. 1, 2, and 3, is the rotating shaft from which motion is to be transmitted to the needle-bar.

D is the wrist-plate, secured firmly upon the shaft 0.

H is the wrist, and I is the pitman or. rod connecting it with a pin, '13, secured in the bar B. The wrist is fitted snugly into an eye provided for its reception in the pitman I, and secured therein by a set-screw, h, or is otherwise rigidly secured to the pitman, and it has firmly secured to'it a short arm, G, which is thus rigidly connected with the pitman.

E and F are two vibrating arms, each pivoted at one end to the wrist-plate D by one of two pins, 6 f, screwed into or otherwise secured in the said plate at two points distant from the axis of the shaft. The other end of the longer arm, E, is pivoted by a pin, 9, to

the arm G of the pitman, and the other end of the shorter arm, F, to the Wrist H. 'The latter armis kept by a collar, f, on the pin f at a sufiiciently greater distance from the wrist-plate than the longer arm, E, to permit the two arms to pass each other in their vibrations across the wrist-plate D, and to permit the arm G to pass between the outer face of E and the inner-face of F, thesaid arm G being connected outside'of E andinside of F, as shown in Fig. l.-

The operation of the wrist H is as follows: When rotary motion is given to the shaft 0 and wrist-plate D, the arms E, F, and G and wrist Hall rotate with the wrist-plate, and the arms E and F are caused to have, in addi-v tion to their rotary motion, an oscillating motion on their respective pins 0 and f, by which means the wrist H is caused to approach and recede from the axis of the shaft and wristplate in the manner illustrated by the diagram, Fig. 4, in which-the red line indicates the path or figure described by the axis of the wrist. Fig. 2 shows the relative positions of the several parts with the wrist at the point j, Fig. 4-that is to say, when it is nearest to the axis of the shaft-and Fig. 3, their relative positions with the wrist at the point k-that is to say, when it is farthest from the axis. In describing this figure, the wrist gives the bar a reciprocating-movement,

' making the said movement very rapid as the bar completes its upward strokeand during the greater part of its downward stroke, and produces a temporary cessation of the movement soon after the upward stroke commences, to gain time for the shuttle to pass through the loop, after whichit again commences slowly but is soon accelerated.

The irregular movement of the wrist may be varied by varying the relative lengths of the arms E, F, and G, and varying the angle formed by the arm G with the pitman. The motion may also be varied by changing the position of either of the pins 6 f upon the plate D.

What I claim as my invention, and desire to secure by Letters Patent, is

The combination, with each other and with the rotating plate D, of the three arms E F G, wrist H, and pitman I, as herein shown and described.

T. A. MAGAULAY. Witnesses:

M. M. LIVINGSTON, HENRY'T. BnowN. 

